A storage system generally includes a computer such as a server computer executing data processing, hereinafter referred to as a “server”, and a storage apparatus communicatively coupled to the server, and is configured to store data processed by the server in the storage apparatus. Data processed by the server can be roughly classified into structured data stored into a database, for example, and other non-structured data. The non-structured data includes data in various formats such as document, image, and sound.
With recent remarkable increase in non-structured data to be stored in a storage system, there have been increasing demands for fast and efficient data backup processing of non-structured data. In addition, in order to minimize storage resources consumed by backup data, a de-duplication function for preventing duplicate storage of same data and a data compression function for reducing the amount of stored data are used in data backup processing.
In the meantime, it is not rare that one storage system includes servers and storage apparatuses supplied by different vendors from the view point of effective utilization of hardware assets and software assets. In this case, different apparatuses within one storage system operate different de-duplication functions and/or different data compression functions. Thus, the execution time required for data backup processing of a unit data size and a data amount reduced by de-duplication are known to vary in some cases depending on the de-duplication functions and data compression functions (hereinafter, collectively referred to as “de-duplication function”), more specifically, depending on which one of the different apparatuses actually executes de-duplication processing and data compression processing (hereinafter, collectively referred to as “de-duplication processing”).
For data backup processing in such a storage system including different de-duplication functions, the execution is usually planned at a time period avoiding normal business hours in day time in order not to affect, for example, routine works utilizing the storage system. For example, assuming that normal business hours are from 8 AM to 6 PM, a time period available for data backup processing is a time window of 8 hours from 8 PM following the business hours until 4 AM of the next day, and the execution of data backup processing is set to complete within this time window. Usually, a correspondence between a server or storage apparatus serving as a backup source and a server or storage apparatus serving as a backup destination of the data sent from the backup source is determined in a fixed manner. In this case, unless a system administrator or the like changes the correspondence, data to be backed up from a particular backup source to a backup destination is processed by a particular de-duplication function implemented in any one of apparatuses on the backup processing path irrespective of a data type. If data amount processed by a particular de-duplication function increases so much, the de-duplication function cannot process data within a data backup processing time window. This is undesirable since routine works are affected by the event.
In view of such problems as described above, for example, Patent Literature 1 discloses a backup system including a backup source computer which stores backup target data, multiple backup destination computers, each of which is coupled to the backup source computer via a network, a backup mode selection means for selecting one backup mode from multiple backup modes prepared in advance, according to a data property of backup target data, and a backup execution means for causing the backup source computer to transfer the backup target data to a backup destination computer selected from the backup destination computers on the basis of the selected backup mode, and causing the backup destination computer to store the data.